Google has reportedly taken action on sites participating in private blog networks, also known as PBNs. On September 18th, Google sent out widespread manual action notices via Google Webmaster Tools to these sites for “thin content” spam.

Private Blog Networks, PBNs, are generally groups of blogs or sites often controlled by one publisher, with the goal of building up links within the network as a way to help particular content rank better in Google. They aren’t really “private” from Google or the public. They can be seen but the “private” name seems to come out of the idea they aren’t really meant for public visitors but instead just to generate links mainly for SEO ranking purposes.

Google considers thin content to be search spam and has a page in their webmaster guidelines explaining they can take action on such type of content.

Some SEOs and Webmasters use these PBNs to artificially inflate their Google rankings either through content spamming or link spam.

It seems as if Google has hit a massive number of web sites utilizing these PBNs over the past several days. Spencer Haws was one webmaster who got hit by the manual action, claiming now he will never use it again.

Here is a screen shot of the manual action Spencer received:

Greg Nunan also shared a screen shot of a manual action for this penalty:

Those who run PBNs are not convinced this is the end for their networks. As reported, Alex from a PBN wrote on a black hat forum that he doesn’t “believe the end of PBNs is somewhere near,” but he did admit “of the current wave of PBN de-indexation.” He still thinks quality PBNs have a shot but clearly, PBNs are something Google is not a fan of.

We asked Google for a comment and they responded they do not comment if it’s about particular manual actions.

We do however believe that this manual action was indeed very widespread and should be seen as a major blow to those using PBNs for search spam.

See our Google Penalties archive for more coverage on past penalties issued by Google.